Evidence has been obtained over the past years that Diabetes Mellitus is a bihormonal disease characterized by excess glucagon secretion as well as inadequate insulin release. We plan to continue investigations relating to the functional regulation of alpha cell secretion in normal subjects and the nature of alpha cell dysfunction in diabetics. Infusion of dopamine itself as well as dopamine agonists and L-Dopa will be used to elucidate the type of autonomic adrenergic or dopaminergic control mechanisms involved in glucagon release. We propose to continue our investigation of agents which suppress glucagon secretion such as somatostatin. Dose response curves will be obtained and analogs of somatostatin will be tested in the hope of obtaining more specific as well as longer lasting effects. It is hoped that a safe and effective adjunct to insulin replacement will be found for the purpose of improving glycemic control after meals in diabetics.